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超疏水性生物表面的研究进展 总被引:1,自引:0,他引:1
介绍了几种天然超疏水生物表面的研究进展,包括蛾翅膀、蝉翼、蝴蝶翅膀、白蚁翅膀、甲虫,蚊子的腿、翅及其复眼,水黾的腿部和荷叶的表面。 对现有的仿生超疏水材料的制备方法及常用作表面修饰的低表面能材料做了简单的归纳与总结。 对超疏水材料研究面临的挑战及以后的发展趋势做了展望。 相似文献
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采用微注射压缩技术,以单步模板法制备表面具有微结构的大尺寸聚丙烯样品.以2种目数不同的筛网为模板,制备的样品表面呈现由微棱和高纵横比的微锥体构成的双级复合微结构;构建由上述2种筛网与2种孔径不同的冲孔板叠加而成的4种模板,制备的样品表面呈现由均匀分布的微柱和其顶面的上述双级复合微结构构成的三级复合微结构.这6种表面的静态接触角均高于150°(即呈现超疏水特性),滚动角在5.5°至大于90°之间变化(即黏附性可在大范围内调节).对在直径较小的微柱上成型数量较少的微锥体和微棱的表面,水滴形成全局非复合润湿状态,从而呈现高粘附特性(花瓣效应);对在直径较小的微柱上成型数量较多的微锥体和微棱的表面,水滴形成局部非复合润湿状态,呈现较高粘附特性;对呈现双级复合微结构或在直径较大的微柱上成型数量较多的微锥体和微棱的表面,水滴形成全局复合润湿状态,呈现较低粘附特性,其中微锥体及其间隙较小的表面呈现荷叶效应. 相似文献
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采用测量接触角和观测偏光显微镜对超疏水表面在冷凝条件下的疏水特性进行了研究, 发现冷凝蒸汽进入超疏水表面的微凸起内冷凝, 表面的疏水特性被破坏, 表面的润湿特性变得不均匀, 部分区域甚至呈现亲水状态. 根据实验结果提出了冷凝条件下粗糙表面表观接触角的计算模型, 并使用冷凝条件下表面接触角的测量结果进行了验证. 相似文献
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超疏水超亲油材料因其在油水分离等领域有广泛的应用前景而引起人们极大关注。 目前,有很多方法可以用来制备超疏水超亲油材料,但因其过程复杂、成本高、环境适应性差限制了其在实际生产、生活中应用。 本文以玉米秸秆为原料,经TiO2 溶胶浸涂并经辛基三甲氧基硅烷修饰后显示出超疏水和超亲油,水滴、油滴在其表面的接触角分别为160°和0°。 研究结果显示,玉米秸秆粉表面的超疏水性源于其表面微纳米复合阶层结构及低表面能化学组成的协同作用。 利用玉米秸秆粉表面的憎水性和亲油性,能将其用于水面油污的吸附和分离,具有分离效率高、稳定性好、可循环利用的优点。 相比于其它材料,以玉米秸秆为原料制备超疏水超亲油的油污吸附剂,原料丰富、成本低、过程简单、易降解、可循环利用,有望在生产、生活中得到应用。 相似文献
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热处理对超疏水性含氟丙烯酸酯共聚物膜表面性能的影响 总被引:3,自引:1,他引:3
以微乳液聚合法和溶液聚合法制备丙烯酸全氟烷基乙基酯和甲基丙烯酸甲酯的共聚物, 以1,1,2-三氟三氯乙烷为溶剂, 采用溶剂挥发成膜法直接制备出超疏水膜, 并研究120 ℃热处理对超疏水膜表面性能的影响. 对于用乳液聚合方法制备的超疏水膜, 随着热处理时间的延长, 滚动角表现出先逐渐增大直至完全不能滚动, 然后重新回复到极小滚动角的特殊变化过程, 而静态接触角只是略微减小, 完全不同于热处理对平滑的含氟聚合物表面接触角的影响. 扫描电镜结果显示, 聚合物膜表面形貌对应出现从微/纳复合粗糙结构到微孔粗化并重新形成微/纳复合多层粗糙结构的变化. 相似文献
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《高分子学报》2017,(2):315-320
以棉织物为基材,利用γ-射线辐射引发甲基丙烯酸十二烷基酯(LMA)接枝聚合,使聚苯乙烯(PS)纳米微球通过接枝链以共价键固定到棉织物上,从而在棉织物表面构筑低表面能的纳米尺度粗糙结构,获得低滚动角的动态超疏水棉织物.傅里叶变换红外光谱(FTIR)分析证明通过辐射接枝,在棉织物上存在PLMA接枝链和PS纳米微球.扫描电子显微镜(SEM)表征证明了PS纳米微球的固定使得棉织物表面呈现纳米尺度的粗糙结构.接触角测试结果证明所获棉织物具有超疏水性能,且相对于仅接枝LMA的改性棉织物,PS纳米微球的固定可以显著降低水滴的滚动角,实现动态超疏水的效果.通过抗弯刚度的测量表征了改性前后棉织物的柔软度,结果表明辐射接枝方法对棉织物的柔软度改变不大,不影响穿着性能. 相似文献
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Mimicking natural superhydrophobic surfaces and grasping the wetting process: a review on recent progress in preparing superhydrophobic surfaces 总被引:1,自引:0,他引:1
A typical superhydrophobic (ultrahydrophobic) surface can repel water droplets from wetting itself, and the contact angle of a water droplet resting on a superhydrophobic surface is greater than 150°, which means extremely low wettability is achievable on superhydrophobic surfaces. Many superhydrophobic surfaces (both manmade and natural) normally exhibit micro- or nanosized roughness as well as hierarchical structure, which somehow can influence the surface's water repellence. As the research into superhydrophobic surfaces goes deeper and wider, it is becoming more important to both academic fields and industrial applications. In this work, the most recent progress in preparing manmade superhydrophobic surfaces through a variety of methodologies, particularly within the past several years, and the fundamental theories of wetting phenomena related to superhydrophobic surfaces are reviewed. We also discuss the perspective of natural superhydrophobic surfaces utilized as mimicking models. The discussion focuses on how the superhydrophobic property is promoted on solid surfaces and emphasizes the effect of surface roughness and structure in particular. This review aims to enable researchers to perceive the inner principles of wetting phenomena and employ suitable methods for creation and modification of superhydrophobic surfaces. 相似文献
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Point-of-need (PON) diagnostics offer promising methods to gather information relevant to health and safety on-site without the requirement for a fully equipped laboratory. In this review, we discuss how liquid-infused surfaces offer a promising platform to expand the capabilities of PON devices in the areas of biological sample preparation and system integration, providing new methods of controlling the movement of droplets and facilitating detection of biological and chemical compounds contained therein. Modifications to the underlying surface structure can be used to passively control the direction of droplet movement, and the careful selection of responsive solid substrates and/or overlying liquids can allow active control through induced temperature gradients, electrical stimulation, and exposure to magnetic fields. Recent work leveraging other advantages of liquid-infused systems such as ultra-low friction, noncoalescence of droplets, and liquid–liquid patterning has demonstrated the unique ways in which this approach can be used to both enhance current detection methods as well as enable new ones. Together, these recent developments in the manipulation of droplets on liquid-infused surfaces point to their significant potential for furthering the capacity of PON devices for both biological and environmental samples. 相似文献
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In this paper, the multilayer films of poly-L-lysine (PLL) and DNA were created on TiO2 nanotube surfaces using the layer-by-layer (LBL) self-assembly technique. Chemical compositions of the assembled multilayered films were investigated by X-ray photoelectron spectroscopy. Biological properties of the multilayered films were evaluated by the biomimetic mineralization and osteoblast cell culture experiments. The results indicated that PLL and DNA were successfully assembled onto TiO2 nanotube surfaces by electrostatic attraction. Moreover, the samples of assembled PLL or/and DNA had better bioactivity in inducing HA formation and promoting osteoblast cells adhesion, proliferation and early differentiation. 相似文献
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《中国化学快报》2020,31(10):2583-2590
Bi/semiconductor photocatalysts have extensively been applied in the production of hydrogen, CO2 reduction and environmental remediation in recent years. This short review summarizes the role of Bi metal as a plasma photocatalyst and cocatalyst. As a cocatalyst, Bi metal can be electron/hole trappers, charge transfer mediators, or oxygen vacancy coordinators. In addition, the preparation methods of the Bi/semiconductor photocatalysts are also reviewed. Challenges and future research directions related to Bi/semiconductor photocatalysts are discussed and summarized, including the use of advanced characterization techniques to refine the reaction mechanism, the difficulties of preparing Bi single atom catalyst, and the improvement of the reduction ability of Bi-based photocatalysts. This review helps understand the reaction mechanisms of the composite photocatalytic systems containing Bi metal and proposes new perspectives for designing the photocatalysts which can control air pollution via a reductive process. 相似文献
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采用阳极氧化法制备了TiO2纳米管/线复合阵列. 利用表面光电压谱(SPS)和场诱导表面光电压谱(FISPS)研究了退火对TiO2纳米管/线复合阵列表面光电性质的影响. 结果表明, TiO2纳米管/线复合阵列在晶化前后的导带边缘均出现了束缚激子态, 晶化前由于自建场较弱, 束缚激子态能在正负电场作用下发生不对称偏转; 晶化后, 晶体结构从非晶态变为晶态, 自建场增强, 束缚激子态对正电场敏感并表现出明显的光伏响应, 而在负电场作用下束缚激子态没有任何光伏响应. 相似文献
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The 2018 report by the Intergovernmental Panel on Climate Change (IPCC) details how rapidly Earth's climate is changing due to rising atmospheric CO2 concentrations. Maintaining a recognizable terrestrial ecosphere over the next eighty years will require, by 2030, a decrease in global CO2 emissions by 45% from their 2010 levels, with zero net global emissions by 2050. However in 2018, global CO2 emissions were 112% of 2010 levels. Our interest lies in the use of sunlight to efficiently recycle CO2 from a waste combustion product, together with water vapor, into hydrocarbon fuels that can be readily stored, transported and used within the current energy infrastructure. While the concept is intriguing until 2019 such a solar fuels technology has been limited by the vanishingly small CO2-to-fuel photoconversion efficiencies achieved. Recently there has been a significant advance in CO2 to fuel photoconversion efficiencies with researchers achieving, in an unoptimized system, over a 6 h period, a Joule (sunlight) to Joule (fuel) photoconversion efficiency of 1%. Just as photovoltaics went from niche market devices of low photoconversion efficiency to highly efficient devices enabling a global industry, such a sunlight-to-fuel photoconversion efficiency suggest utility-scale implementation of a sunlight-powered recycled-CO2 to hydrocarbon fuel technology is realistically achievable in the near future. With an aim towards enabling significant advances in the field, leading to translation of the technology from laboratory to industrial-scale application, we examine what we believe are the key opportunities for achieving significant advances in sunlight-to-fuel photoconversion efficiencies. 相似文献
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Yuhong Zhang Hailiang Xu Yongxi Xu Huaxing Zhang Yanguang Wang 《Journal of photochemistry and photobiology. A, Chemistry》2005,170(3):532-285
A series of Nd3+, Pr3+, Er3+, and Dy3+ (0.25–5 at.%) homogeneously doped nanocrystalline titanium dioxides (Ln/TiO2) were prepared by an easy sol–gel technique, and the roles of lanthanide doping on the photocatalytic activity in the degradation of rhodamine B (RB) in aqueous solution were studied. Both the concentration of the lanthanide dopant and calcination temperature showed significant effect to the photodegradation of RB. The photocatalytic activity of pure titania was drastically decreased when calcination temperature was at 700 °C, while the high photocatalytic activity was still maintained for lanthanide-doped samples. HPLC-MS method was used to study the degradation process, and it is demonstrated that the degradation of RB catalyzed by Ln/TiO2 was principally go through with a stepwise de-ethylation photochemical process. 相似文献
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The nanostructure of a biomaterial surface has strong influence on cell behavior. The migration of cells on nanostructured surfaces, however, has not been investigated so far. In this study, we used PCL/PEG diblock copolymers as model surfaces to examine the effect of nanoislands on migration of different cells, including fibroblasts and endothelial cells. The water sliding angle of the substrates was measured. The cell migration rate was examined under a real-time optical microscope. It was found that a greater cell migration rate correlated with the smaller sliding angle of the substrate. 相似文献
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Inorganic arsenic (As) displays extreme toxicity and is a class A human carcinogen. It is of interest to both analytical chemists and environmental scientists. Facile and sensitive determination of As and knowledge of the speciation of forms of As in aqueous samples are vitally important. Nearly every nation has relevant official regulations on permissible limits of drinking water As content. The size of the literature on As is therefore formidable. The heart of this review consists of two tables: one is a compilation of principal official documents and major review articles, including the toxicology and chemistry of As. This includes comprehensive official compendia on As speciation, sample treatment, recommended procedures for the determination of As in specific sample matrices with specific analytical instrument(s), procedures for multi-element (including As) speciation and analysis, and prior comprehensive reviews on arsenic analysis. The second table focuses on the recent literature (2005–2013, the coverage for 2013 is incomplete) on As measurement in aqueous matrices. Recent As speciation and analysis methods based on spectrometric and electrochemical methods, inductively coupled plasma-mass spectrometry, neutron activation analysis and biosensors are summarized. We have deliberately excluded atomic optical spectrometric techniques (atomic absorption, atomic fluorescence, inductively coupled plasma-optical emission spectrometry) not because they are not important (in fact the majority of arsenic determinations are possibly carried out by one of these techniques) but because these methods are sufficiently mature and little meaningful innovation has been made beyond what is in the officially prescribed compendia (which are included) and recent reviews are available. 相似文献